Clinical relevance of cluster analysis in phenotyping allergic rhinitis in the paediatric population of the Kuyavian-Pomeranian voivodeship, Poland.

Introduction: Allergic rhinitis (AR) is the most common allergic disease in the world, and additionally, its prevalence is successively increasing. Children with AR constitute a heterogeneous group of patients differing both in the course of AR and in the frequency of asthma coexistence. It is possible to identify children with AR at risk of a more severe course of the disease by analysing the potential family, environmental and clinical factors related to the development of the disease; the findings will help identify patients with a higher risk of developing asthma in the future, and who will benefit the most from early allergen-specific immunotherapy.

Aim: Evaluation of clinical relevance of cluster analysis in phenotyping AR based on an analysis of selected clinical and environmental factors.

Material and methods: The study sample was 80 children (7-17 y.o.) with AR, including 28 children with associated asthma. The effects of AR symptoms on the patients daily functioning, skin prick tests (Allergopharma), allergen-specific IgE for airborne allergens (Biocheck GmbH), total cholesterol, cholesterol high-density lipoprotein (HDL), cholesterol low-density lipoprotein (LDL), triglyceride levels in the blood (ARCHITECTcSystem), FeNO and nNO concentrations (HypAir FeNO Medisoft) and results of methacholine challenge test (Lungtest 1000Ispa) were analysed.

Results: Four clusters of patients with AR were extracted, differing in the incidence and severity of AR symptoms and the coincidence of asthma. Most of the children from cluster 1 (n = 24; 85.71%) and cluster 2 (n = 15; 78.95%) had persistent AR, while most of the children from cluster 3 (n = 11; 73.33%) and cluster 4 (n = 14; 77.78%) had intermittent AR. The co-occurrence of asthma was significantly higher in cluster 1 than in other clusters (p = 0.0002). Children in clusters 3 and 4 reported a lower impact of AR symptoms on daily functioning (p = 0.0153). Children in cluster 1 had significantly more often an abnormally high total cholesterol level (p = 0.033) and in cluster 4 significantly more often abnormally high triglyceride levels (p = 0.009) were observed. Patients in cluster 2 were significantly less likely to have abnormal high LDL levels (p = 0.015).

Conclusions: Children with AR from the Kuyavian-Pomeranian voivodeship differing in the course of AR, the frequency of coexistence of asthma, and occurrence of lipid parameter abnormalities.